public partial class Main : Form
{
public void button_Click(object sender, EventArgs e)
{
//here I want to call function runtime() from SchedulingTimer class
// in oder to run afunc() every second or any Interval
}
public void afunc()
{
Message.Show(textbox1.Text);
}
}

And I have a Timer Class:

public class SchedulingTimer
{
public static void runtime()
{
Timer myTimer = new Timer();
myTimer.Elapsed += new ElapsedEventHandler(DisplayTimeEvent);
myTimer.Interval =10000 ; // 1000 ms is one second
myTimer.Start();
}
public static void DisplayTimeEvent(object source, ElapsedEventArgs e)
{
//call function from main which have agrument textbox.Text
afunc();//or any function which variable sended from Main form
}
}

But when I call afunc in DisplayTimeEvent method it has some error cause this is a static method so cannot access textbox1.Text. I think my code has some mistake.

UPDATE:

I set myTimer.Enable= true ,then, I click on Button but nothing
happend. It seems afunc() doesn't work.

create instance of Main method in DisplayTimeEvent. Main objMain=new Main();objMain.afunc(); and there are some detail in afunc: